An optocoupler moves signals between two circuits using light instead of electricity. That way, the input and output stay electrically separate; there is no direct connection, just light doing the job. In this guide, you'll learn how they work and how you can use one in your own projects. Optocouplers are very useful when you need to isolate different sections of a circuit, for example in power. An optocoupler, also known as photocoupler or opto-isolator, is a device which can transfer an electrical signal across two galvanically-isolated circuits by way of optical coupling. Unlike transformers or capacitors, which can only transfer AC signals across the isolation barrier, optocouplers can. I have built this circuit using an optocoupler: simulate this circuit – Schematic created using CircuitLab How would this circuit change if I wanted to detect 12v instead? Is it just a matter of switching R2 for a higher value? I see that voltage dividers can also be used for the same job, but I. The sensor is an LJA183-8-Z/BX and I have it powered with 24V. 3V and just connects to a switch. I was wiring it up like this; I'm thinking that the photocoupler will act as a switch on the 3.
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